Signal horn



R. D. BUELL SIGNAL HoRN Sept. 5, 1950 Filed Dec. 29, 1945 Patented Sept. 5, 1950 UNITED STATES PATENT oEElcE SIGNAL HORN Roy D. Buell, Chicago, Ill.

Application December 29, 1945, Serial N o. 638,203 2 Claims. (o1. 11e-142) The present invention relates to a signal horn and more particularly to an alarm or signal horn for use on railway trains, ocean-going ships,

` buses, trucks, other motor vehicles, motor and sailboats, and other conveyances, also used as a signal for bridges, in factories and the like.

The signal horn of the present invention is one operated by high pressure air, of the type designed to give signals or alarms to avoid accidents under conditions where the usual type of horn would be inadequate. The lengths and diameters of the bells of the horns determine the tones, and the longer bells of larger diameter produce deeper and mellower notes of directional carrying power.

The present invention has to do with that type of signal horn or alarm wherein a vibratory unbalanced valve is utilized to produce the desired sound, and has for an important object the provision of a casing forming an air chamber certain Awalls of which support air outlet tubes in axial alignment and with the tubes arranged with their adjacent ends spaced apart sufficiently to receive an unbalanced vibratory valve disc between them, which disc vibrates to create sound in a horn connected to an air tube, when air under pressure is admitted to the interior of the casing, and with at least one of said walls movable with respect to the other wall to provide clearance for the valve disc when it is vibrated under high air pressure conditions.

Another object of the present invention is to provide an air pressure signal horn construction using an unbalanced vibratory disc valve to create sound, wherein the gap in which the valve vibrates may be varied in accordance with variable operating air pressures.

A further object of the present invention is to provide a casing forming an air chamber which casing has flexible wall means to provide clearance for an unbalanced valve for diiferent operating pressures.

A still further object of the present invention is to provide a construction of signal horn having greater longevity under strenuous working co A v tional view throughthe arrangement of Figure 1; Figure 3 is a transverse vertical sectional view'- 2 vtaken in the plane of line III- III of Figure 2; and

Figure 4 is a graph showing the relationship between air pressure and wall deflection for a given example.

The drawing will now be explained.

Figure l illustrates two horns, A and B, extending in opposite directions, horizontally, from a casing C which is provided with a'base 5 whereby the horn structure may be mounted for use.

The h-orns A and B may be of any appropriate form and dimension to produce the character and tone of sound or note to be produced. In order that the produced note may be one of pleasing' quality, and especially distinctive for signaling purposes, I prefer to utilize a form of horn similar to that of the ordinary slide trombone in which the musical tone is produced by the bel part of the horn. f

The form of device chosen as an exemplifi'cation of the present invention includes a casing C which is formed as a casting, such as a die casting, preferably circular in vertical cross section, with the casing having a rigid apertured side wall 5 and a peripheral wall I from which an annular iiange 8 extends. The other side of the casing is open. The central portion of the casing is preferably formed with a tubular boss, or sleeve, 9, with a portion of the sleeve lying inwardly of the inner surface of the wall 5, as at IU, and another portion of the sleeve lying outwardly of the outer surface of the wall I5, as at I I, although this construction is not essential, but is satisfactory. The casing C has a threaded opening I2, in a lower portion thereof, to receive the threaded end of a pipe I3 which is connected to the base 5.

If desired, the base 5, the'pipe I3 and the casing E could be made as an integral casting. Thev base 5 is provided with suitable holes (not shown) for receiving screws or bolts for securing the structure in place on a suitable support.

The boss or sleeve 9 is formed to receive an air outlet tube or the like. In the present instance, the tubular portion of the horn B is shown as inserted in the sleeve 9, with its inner end projecting inwardly, slightly, of the inner end of the portion IIJ of the sleeve, as may be observed in Figure 2. The horn B is suitably secured in the sleeve 9 so as to remain in connected relation regardless of the strenuous conditions of o-peration of the means to which the horn may be applied.

Closing the open Side of the casing E is a flexible or yieldable wall, such as a diaphragm I4 which has its marginal portion secured to the flange 8 of the casing by suitable fastening means, such as screws I5. The center of the diaphragm I4 is apertured to receive an air outlet tube, the outlet tube in the present instance being a portion of the horn A. The horn A is secured to the diaphragm I4, in permanent relationship, as by soldering at I6, or in any other suitable manner. The horn A is mounted in the diaphragm I4 in axial alignment with the horn B and arranged so that theinner .end .of the. horn will .be spaced a slight'distancefrom the innerffend of thehorn B to provide a gap to receive therein an unbalanced valve I1, and provide sufcient space to enable vibration of the valve between the adjacent ends of the horns or air outlets. Therv-alve l1 is in the form of a disk, which may be made of metal, a plastic or other suitable material.

In order to support the disc valvefh'linfvibratory position between the adjacent ends of the horns or air outlets, and to mount it-'ffor `free movement between these ends, under the influence of airwpressure, -Tmeansarefprovided supported, as for example, by the portion l0 of the sleeve'aof *boss `structure'for' iloosely-.coniining lland :.supl'gm'xiting the Yperip'heral'rportions yof the disc valve.

The supporting structure is slightly Vzgreater in diameter thanathex'diameter. -ofthe ldisc yvalve so 'htithe'- valve may fffreely @vibrate vx.Without re- 'f'straint other fthan- Aresti-ai-nt:against:displacement ffomwbetweenfthezadjacentiends of the horns.

Theillustratedformmzretaining :means .forithe iscfvalvefl 'lucomprises 1a vcage formed *by 1 a .plufarlityffo pinsffW-projecting #from the portion l0 mifthebossf,iintoithez-chamber of thefcasingsur- `we rlmi'ling Ithe'rspace foregap between'rthe' adjacent renderli-'fthehornsffor'receiving the disc Yvalve .'"l-'l randhdlding it :in 'place f between ythe .ends .of'the llxorns. l"The pinsll 8,*'forming the cage, Aareshown ras-'duur in number, arrange-d':invequidistant circumferentially spaced relationraboutr'the :axis Aof leasing. it' isittrbe understood that fthe disc whre' Fl ani'ghtT-bef'retain'ed 'in'rpositi'on between thevadjaeent lends offthehorns, by at 'least three lzofsuch pins', but'tofreduceifri'ction vto v arminimum, morefthan'threeearepreferably utilized. -It iis to rbe'uriders'toodlthat more v"than `'three Vsuch pins marylbe used, and itisfalso to be understoodthat 'zhencage may'be-'formed inra 'manner otherwise -harlbyithefpinsilthemainlrequirement beingthat iit 'loosely vconfineith-e :peripheral *portion of the *dscfvalvefwithout undue'friction.

'When'the' @horn vs'truc'tureis f mounted f or use, 'fthe'pipe' L3 iscon'necte'd'lto asource'oflcompressed 'fairfslrch'iforcexample' as :an air compressor, or 'a .tankontaining :compressed air. Installed in -tsuch'connection is a-rsuitable valveor controlling -fndm'ission of compressedairitothe interior of the 'fcasing fior operating'fthe horn.

hir press ure-'utilized `in signalhornsfo'fthe char 'sichert-hereinfdisclosed 1'is 'sometimes as `high as 20) 2156wpounds-persquare rinch. Under certain .conditions 'the =pressure^might be higher.

' "Itmfillbeurrder'stood' that when compressed air is-ra'drriittedto ithelinteriorof y'the casing zlgthe #disc Yvalveff'lwilli-lee vibrated; producing the tonal moundsf-for-f-which the'ihornsfare designed. It is epos'slbla-byeproper design and d-mension of`A the hornsto 1producefdeep and'mellow tones `of lgreat marrying-power. '"Thefperiod-of vibration oithe "dscfva-lve illiisfcontrolled by the ltonal "frequency ofllrhe' hornfbe'll.

lorns ofthe characterr herein 'mentioned -have -fbeenused andare :being used on ships, high speed ixailwaytrainm such'asxsome of `the streamliners, motor trucksiandbusesrand other conveyances foperating zundericonditions'requiring the giving infraudihle zwarnirrg signals, far inadvance of .the umovement'fofdahe:particularconveyance;and for 4signal purposes 'inflfactories andthe like.

'fhevvibration fof the :disc valvel I1 :is f attained fdueto'theraspiratorfeffectcreated at the openings into the horns A and B within the chamber C. As previously mentioned air is admitted to the chamber C under pressure and escapes from the chamber Athrough the adjacentend openings of A'the 'tubes A and 'B. The disc I 'l-isfloatingly disposed between the adjacent tube ends by the pins t8. When air escapes under pressure through an opening, it escapes at a velocity directly proporlti'onal to the pressure of the air Within the coniining chamber. When iluids pass over a surface at a high velocity, as when air under pressure escapes-through asmall opening, a low pressure areais created about the opening. Unsecured bodies are attracted toward the low pressure area, and if their size permits they will follow the fstream .Uffiuids through 'the op ening.

YIlhusg Lit is 'hereapparent l,that tif air y'unrler'msurezescapes .throughzone of `rthese openings'he *.v'alvefdisc Il :is Vattra/cte'd Y'towardithe "lowipressmse fareafsurroun'ding that opening until thesvalve-t'l closes fthefopening. "Thereafter, :the air :must :escapethrough the opening ofthe opposed/'.tube. switching' the low v.pressure :area'fandrcausmgthe .va'lve'lrl to'move toward the .'othertubezopening. f'l'ihe rate o'f.'sv\zitcl1ing .and vibration ofithewalve iii wis :directly- .proportional #to 'the 4"air :pressure :within the chamber :and Ito' 'the rate of'fescapei'fof therair initial lvibrationrof' the'valve |'1 :is 'created i-when'air Ais'escaping fromboth the itdbes Arand'B, because it is not possible for the valve I.1fto'^be Vfequ'i-fspaced between thezopposed 'adiacenti-.tube openings, :so aszto :be equally iattr-acted'toward .both.

Vlt is'necessarythat'the discvalve be veryfre'ely 7vlibra'table and supported 1in a manner to ereduce zfriction :to a minimum. 'The "herein described :method of supporting 'the valve 'gives Avery'satis- 'iractery :results in horn foperation.

.'The Vsignal hornwwill operate over a wide 'pres- 40 vsurefrange, from va few ounces of pressure to sevferal'hundred pounds, the greater the-pressure "the greater fthe increase in Atone volume 'or Tloudness The provision of the "exible or yieldablewdll or=diaphragm 14, :asoneof the walls' for `the air chamber within the casing 6, enablesvslight'out- @ward rmovement o'f fthe wa'll under high air-pres- '.sure conditions to 'increase' the gap between Athe #tube ends -to enable the `valve disc Ato function properly, by slightly increasing thel capacity-of "the'icasing chamber. vThe full 'line vrepresentation of the diaphragm in'Figure'Z is the position fit foccupies 'when' the pressure is low, rand the .'dotted fline position is .another lposition assumed by'the:diaphragmiwhen the pressure elevated.

"It ris tozbe Aunderstood that movement ofthe central portion of the diaphragm M,"to dotted'llne positionof Figure 2, will move'the innererid of 'thefhornftube A-.a 'slight distance away from the adjacent yend Aof the'horn tube 'B thus .providing additional clearance for the disc valve Wheniit 'f-isfv'ibrated under high air-.pressure conditions.

vvl'igure4is Aa 'graph illustratingthe relation- Aship V`between' air Vpressure 'in a Vcasing such as 'casing' C .iandthe amount fof flexible Wall 'or'dia- ,-.phragm'itleection o`f Va bronze 'diaphragm' 4"fin diameter zand i having a thickness 'of ;082'

".Thezordmaterrepresents air ypressure infpolms per square inch anditlre; abscissai the Jdiaphragm zrdeection pinches.

Itfwillbe znoted, therefrom, rthat v:the :deflection 0f the gap, due to air pressure variation, Willibe suchazsftoxpermit vibration'fo'f thev discvvalve to -g-produce pleasing, audiblel sound.

It isxto llle-.understood that a diaphragm of diierent thickness would have a different amount of deliection.

It is within the purview of this invention to construct a casing having both the tube supporting Walls flexible or yieldable, in which event the diameter of the casing would be reduced below that necessary when only one wall is flexible or yieldable.

Instead of two horns as illustrated, either horn A or B may be omitted and a. short open-ended tube substituted in place of the omitted horn. The principle is the same with a single horn, but in that case the warning sound emitted is largely sent in one direction instead of in opposite directions.

The word diaphragm is herein used to designate any thin curtain or Ipartition which may vibrate. That is to say, the term diaphragm is used to refer to a thin sheet of material, generally circular and restrained by having its periphery clamped but otherwise free to vibrate under the action of some driving force.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention, and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

l. A fluid pressure actuated signal horn construction capable of producing audible signals throughout a wide range of pressure which may vary from a few ounces to substantially over 200 pounds per square inch and including air chamber means of variable capacity which automatically adjusts itself to the fluid pressure delivered to it, comprising a box having one open side, v

a flexible membrane closing said open box side and capable of movement with respect to the plane of said open side to vary the volumetric capacity of said chamber within certain limits, said movement being dependent solely upon fluid pressure variations within said box, two air outlet tubes projecting into said chamber and having their inner ends adjacent but spaced apart, one of said tubes passing through and immovably fastened to said membrane to move with it toward and away from the other of said tubes as the membrane is flexed by pressure differentials in said chamber, the other of said tubes passing through a portion of said box in axial alignment with said one tube and immovably fastened to said box portion, a vibratory valve disk supported between the adjacent ends of said tubes to alternately open said tubes to pressure, and said box having a pressure inlet.

2. A fluid pressure actuated horn comprising a casing with an apertured side and an opposed open side, a relatively stiff resilient diaphragm closing said open side and having an aperture aligned with the aperture in said apertured side, a, vibratory valve in said casing between said apertures and arranged to alternately open and close said apertures, a fluid inlet for said casing, and said diaphragm being arranged to move away from the apertured side of the casing as fluid pressures in the casing increase and to return toward said apertured side responsive only to a decrease in said fluid pressure whereby said valve will have an operating space between the apertures which varies directly with variations in said fluid pressures.

ROY D. BUELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,767,740 Buell June 24, 1930 2,281,539 Grover Apr. 28, 1942 FOREIGN PATENTS Number Country Date 809,083 France Dec. 3, 1936 

